Variable feed pump and related method



June 23, 1964 c o VARIABLE FEED PUMP AND RELATED METHOD 2 Sheets-Sheet 1 Filed Nov. 23, 1962 INVENTOR. THE'ODORE C'fl/VTOR HLfl/V K. ROBERTS June 23, 1964 T. CANTOR 3,138,104

VARIABLE FEED PUMP AND RELATED METHOD Filed Nov. 23, 1962 2 Sheets-Sheet 2 INVENTOR. THEODORE C'fl/V 70R 19L 4N K. ROBE/RTs United States Patent 3,138,104 VARIABLE FEED PUMP AND RELATED METHOD Theodore Cantor, Yonkers, N.Y., assignor to Manostat Corporation, New York, N. Y. Filed Nov. 23, 1962, Ser. No. 239,668 6 Claims. (Cl. 103-37) This invention relates to variable feed pumps and to related methods.

It is an object of the invention to provide an improved variable feed pump.

It is a further object of the invention to provide a pump having an improved throttling mechanism.

It is still another object of the invention to provide an improved variable feed pump wherein the movable components are not exposed to the associated fluid.

Still another object of the invention is to provide an improved variable feed pump which enables rapid and convenient changing over from one fluid to another.

Yet another object of the invention is to provide an improved variable feed pump wherein there are no cleaning problems or danger of contamination.

It is still another object of the invention to provide an improved variable feed pump wherein acids, bases, toxic and sterile liquids and gases may be handled with equal ease.

In achieving the above and other of its objectives, the invention contemplates the provision of a variable feed pump wherein is employed a coplanar arrangement of rollers revolvable about an axis and adapted for applying, for example, cyclical and progressive compressive forces to a tube held in an adjacent support whereby a pumping operation is effected on the fluid supplied to the said tube.

According to a feature of the invention and, as will be discussed in greater detail hereinafter, the invention proposes the use of a means to apply a compressive force at at least one fixed point on the tube in adjustable manner in order to controllably throttle the passage of fluids through the said tube.

An advantage of the invention is that structures provided in accordance therewith are readily susceptible of mass production techniques and can be readily maintenanced and repaired.

Another advantage of the invention is that structures provided in accordance therewith may be readily disas sembled for purposes of changing the components therein to adapt to different magnitudes of fluid flow.

A further object of the invention is to provide improved pumping methods in accordance with which fluid is supplied to a tube to which is applied a compressive force progressively along the same to effect a pumping action while at the same time an additional and adjustable compressive force is applied to a limited section of the tube to throttle the flow of fluid therethrough.

Other objects, features and advantages of the invention will be found in the following detailed description of a preferred embodiment as illustrated in the accompanying drawing in which:

FIGURE 1 is a perspective view of a variable feed pump provided in accordance with a preferred embodiment of the invention;

FIGURE 2 is a front view of the pump and throttling mechanism provided in accordance with the invention;

FIGURE 3 is a top plan view of one of the components of the pumping mechanism;

FIGURE 4 is an end view of the component of FIG. 3;

FIGURE 5 is an end view of a component of the throttling mechanism of the invention; and

FIGURE 6 is an end view of the component of FIG. 5.

The perspective View of the variable feed pump of the invention as illustrated in FIG. 1 shows that said pump comprises generally a casing C, a pumping mechanism P,

a throttling mechanism T and a control switch S. The casing C is partially broken away to expose a motor M (diagrammatically illustrated) which is connected to the pumping mechanism and supplies a rotatable force therefor.

FIG. 2 is a plan view showing the pumping mechanism and the throttling mechanism in combination.

The pumping mechanism comprises generally a support 10 adapted for being maintained in position on the casing by thumb screws 12 and 14. Said pumping mechanism further comprises a rotatable shaft 16, a lever 18 and two rollers 20 and 22 rotatably mounted on pins 24 and 26 connected at opposite extremities of said lever 18.

The shaft 16 is coupled to the motor (see motor M in FIG. 1) and is adapted to be rotated thereby. Lever 18 is a generally planar member fabricated of metal or other suitable material having the necessary strength and is generally perpendicular to and fixed for rotation with the shaft 16.

Rollers 20 and 22 are either fixed on pins 24 and 26 or rotatable on said pin. The rollers 20 and 22 are intended to revolve about the axis 28 defined by the shaft 16.

In so revolving about said axis the portions of the rollers 20 and 22 which are most remote from this axis define a circle, the diameter of which is indicated by reference 30. Said rollers are intended to apply progressive and compressive forces to a tube 32, as will hereinafter be described in greater detail.

For purposes of supporting tube 32, the support 10 (see also FIGS. 3 and 4) is provided with a groove 34. This groove 34 is located in the semi-circular section 36 of said support, the groove 34 opening inwardly and radially towards the axis 28.

At the extremities of semi-circular section 36 are provided two rectilinear sections 38 and 40, which are aligned in parallel with one another and which are provided with grooves 42 and 44 respectively, which constitute extensions of groove 34 and cooperatively constitute therewith a receptacle adapted for accommodating the aforesaid tube.

The above-noted receptacle is intended to support the tube 32 and provide the same with a U-shaped configuration, whereby the tube consists of an arcuate section 46 and two rectilinear sections 48 and 50, whereof the section 48 may be considered as being the inlet section and the section 50 may be considered as being the outlet section.

The groove 34 is in the shape of a semi-circle, having a diameter indicated by reference 52, which is greater than the aforesaid diameter 30 by a determinable amount. The tube 32 is a resilient flexible tube, preferably of circular cross-section, having a diameter which exceeds the difference between radii 30 and 52 so that said rollers 20 and 22 can operate to apply a cyclical and progressive set of compression forces to the tube 32 to effect a pumping action on fluid supplied thereto.

The whole of the above arrangement is supported on the casing (see FIG. 1), due to the mounting of the support 10 on the casing by means of a neck 54 (FIG. 4), through which extends a bore 56, through which may extend the shaft 16 in a suitable bearing.

With the pumping mechanism so fixed, a threaded post 58 is provided perpendicular to the casing and parallel to the shaft 16, which locates the site for the aforenoted throttling mechanism.

Generally, this throttling mechanism comprises a plate 60 slidably supported on the post 58 and a control knob 62 threadably engaging and adjustably positioned on said post.

more clearly, it being seen herein that said plate includes two downwardly depending and substantially identical extensions 64 and 66.

FIGS. 5 and 6 shows the configuration of the plate 60 The lowermost extremities of said extensions consist of a generally triangular element 68, the cross-sections of which are arcuate, as is best seen in FIG. 5. Said lowermost extremities are furthermore provided with a rough casting surface equivalent to a heavy knurl finish, whereby appropriate engagement may be made with the portions 48 and 50 of the tubing 32.

The extremities or extensions 64 and 66 are spaced apart by a distance equal to the distance between the portions 48 and 50 of tube 32, so that when plate 60 is urged downwardly on post 58 by means of control knob 62, a compressive force is applied along limited portions of said tube, in order to effect a throttling action.

It will be noted that this throttling action is applied both to the inlet and outlet ends of the pump portion of the tube, so as to avoid the generation of unsuitable vacuums.

For purposes of set-up and operation, the support can be removed by removal of thumb screws 12 and 14 and a tube 32 may then be appropriately positioned in said support. A firm contact between the tube and the periphery of the groove along the entire extent of the latter is preferred.

The support 10 is then replaced on the casing by means of screws 12 and 14 and a fiuid supply is connected to the inlet extremity of the tube.

Throttling adjustment may then be made by clockwise or counterclockwise rotation of knob 62 threadably engaged with post 58, whereby compressive forces are imposed by extremities 64 and 66 against the portions of tube 32 in grooves 42 and 44.

The tube 32 is sufficiently resilient and has sufficient shape-retaining capabilities as to yieldingly resist action of extremities 64 and 66 thereagainst so that when pressure is released by appropriate rotation of knob 62 the plate 60 is forced upwards.

Different diameters of tubing can be accommodated in the support 10 by the use of appropriate liners (not shown). Moreover, the tube 32 may be readily replaced by a new and clean tube, by means of very simple assembling and disassembling operations.

It will be appreciated that the procedure suggested in accordance with the use of the above apparatus may be employed in connection with other and patentably distinct apparatus provided, for example, that the method consists of supporting a resilient flexible tube in U-shaped configuration and supplying a fluid to this tube while applying a plurality of compressive forces against the tube cyclically and progressively along the tube at the interior of the arcuate portion of the U. Further according to a feature of the invention equal compressive forces may be applied against the rectilinear portion of the U to throttle the flow of liquid through the tube.

It will be appreciated, moreover, that the method of the invention need not necessarily be restricted to maintaining the tube in U-shaped configuration, it being further possible to employ other configurations as further embodiments of the invention employing both the use of a progressively displaceable compressive force and a further compressive force applied against the associated tube at a limited portion thereof.

By employing silicon or tygon tubing of approximately /2 inch outer diameter, with a inch wall, with the components of the support being appropriately dimensioned, it has been found possible with a rotation of 500 revolutions per minute of the pumping mechanism to adjust a delivery rate from 4.7 liters per minute at 2 lbs. per square inch, to a delivery rate of just a few drops per minute.

There will now be obvious to those skilled in the art many modifications and variations of the structure and methods set forth above. These modifications and variations will not, however, depart from the scope of the invention if defined by the following claims.

What is claimed is:

1. In a variable feed pump comprising a casing, a motor Within said casing, a switch on the outside of said casing and coupled to said motor for selectively actuating the same, a rotor on the outside of said casing and coupled to said motor to be driven by the latter; said rotor including a shaft defining an axis of rotation and coupled to said motor, a lever perpendicular to and fixed on said shaft, pins on said lever at opposite extremities thereof and at equal distances from said axis, coplanar rollers of equal diameter rotatable on said pins, said rollers, with said shaft rotating, describing a circle about said axis, said circle having a radius equal to the distance between said axis and the portion of each said roller most remote from said axis, a support including a semi-circular section and two rectilinear sections extending in parallel from the extremities of said semi-circular section, said semi-circular section being provided with an inwardly opening groove facing said shaft and concentric with said axis and having a radius greater than the first said radius, said rectilinear sections defining facing grooves constituting extensions of the first said groove and constituting therewith a receptacle of generally arcuate cross-section, and a flexible tube positioned in said receptacle and of a normally circular cross-section having a diameter greater than the ditference between said radii whereby said rollers are adapted for locally and progressively compressing the said tube, the improvement consisting of a threaded post between said rectilinear sections, a plate slidably displaceable on said post and including two extensions adapted for compressing said tube in said rectilinear sections to throttle liquid fiow into and out of said tube, the latter said extensions including generally triangular extremities for engaging said tube, and a knob adjustable on said post and adapted for controllably displacing said plate and triangular extremities towards said tube.

2. A variable feed pump comprising a casing, a motor within said casing, a switch on the outside of said casing and coupled to said motor for selectively actuating the same, a rotor on the outside of said casing and coupled to said motor to be driven by the latter; said rotor including a shaft defining an axis of rotation and coupled to said motor, a lever perpendicular to and fixed on said shaft, pins on said lever at opposite extremities thereof and at equal distances from said axis, coplanar rollers of equal diameter rotatable on said pins, said rollers, with said shaft rotating, describing a circle about said axis, said circle having a radius equal to the distance between said axis and the portion of each said roller most remote from said axis, a support including a semicircular section and two rectilinear sections extending in parallel from the extremities of said semi-circular section, said semi-circular section being provided with an inwardly opening groove facing said shaft and concentric with said axis and having a radius greater than the first said radius, said rectilinear sections defining facing grooves constituting extensions of the first said groove and constituting therewith a receptacle of generally arcuate cross-section, a flexible tube positioned in said receptacle and of a normally circular cross-section having a diameter greater than the difference between said radii whereby said rollers are adapted for locally and progressively compressing the said tube, a threaded post on said casing between said rectilinear sections and parallel to said shaft, a plate slidably displaceable on said post and including two substantially identical extensions adapted for compressing said tube in said rectilinear sections to throttle liquid flow into and out of said tube, the latter said extensions including generally triangular extremities with arcuate cross-sections for engaging said tube, and a knob threadably engaging said post for controllably displacing said plate and triangular extremities towards said tube, said tube being of a resilient material and yieldingly resisting the displacement of said extensions thereagainst.

3. A pump as claimed in claim 2 wherein said triangular extremities have rough surfaces.

4. A pump as claimed in claim 2 wherein said triangular extremities are perpendicular to said plate.

5. A variable feed pump comprising coplanar rollers of equal diameter rotatable about a common axis and adapted for describing a circle having a radius equal to the distance between said axis and the portion of each said roller most remote from said axis, a support including a semi-circular section and two rectilinear sections coplanar with and extending in parallel from said semi-circular section, said semi-circular section being provided with an inwardly opening groove concentric with said axis and having a radius greater than the first said radius, said rectilinear sections defining facing grooves constituting extensions of the first said groove and constituting therewith a receptacle of generally arcuate crosssection, a tube positioned in said receptacle and of a cross-sectional dimension greater than the difiference between said radii whereby said rollers are adapted for locally and progressively compressing the tube, a plate including extensions adapted for compressing said tube in said rectilinear sections to throttle liquid flow into and out of said tube, the latter said extensions including generally triangular extremities with arcuate cross-sections for engaging said tube, and means for controllably displacing said plate and triangular extremities toward said tube.

6. A variable feed pump comprising a rotor including a shaft defining an axis of rotation, a lever perpendicular to and fixed on said shaft, coplanar rollers at 0pposite extremities thereof and at equal distances from said axis, and of equal diameter, said rollers, with said shaft rotating, describing a circle about said axis, said circle having a radius equal to the distance between said axis and the portion of each said roller most remote from said axis, a support including a semi-circular section and two rectilinear sections extending in parallel from the extremities of said semi-circular section, said semi-circular section being provided with an inwardly opening groove facing said shaft and concentric with said axis and having a radius greater than the first said radius, said rectilinear sections defining facing grooves constituting extensions of the first said groove and constituting therewith a receptacle of generally arcuate cross-section,

a flexible tube positioned in said receptacle and of a normally circular cross-section having a diameter greater than the difference between said radii whereby said rollers are adapted for locally and progressively compressing the said tube, a threaded post parallel to said shaft, a plate slidably displaceable on said post and including two substantially identical extensions adapted for compressing said tube in said rectilinear sections to throttle liquid flow into and out of said tube, the latter said extensions including generally triangular extremities with arcuate cross-sections for engaging said tube, and means on said post for controllably displacing said triangular extremities against said tube.

References Cited in the file of this patent UNITED STATES PATENTS 459,055 Truax Sept. 8, 1891 2,097,028 Gates Oct. 26, 1937 2,955,543 Daniels Oct. 11, 1960 

1. IN A VARIABLE FEED PUMP COMPRISING A CASING, A MOTOR WITHIN SAID CASING, A SWITCH ON THE OUTSIDE OF SAID CASING AND COUPLED TO SAID MOTOR FOR SELECTIVELY ACTUATING THE SAME, A ROTOR ON THE OUTSIDE OF SAID CASING AND COUPLED TO SAID MOTOR TO BE DRIVEN BY THE LATTER; SAID ROTOR INCLUDING A SHAFT DEFINING AN AXIS OF ROTATION AND COUPLED TO SAID MOTOR, A LEVER PERPENDICULAR TO AND FIXED ON SAID SHAFT, PINS ON SAID LEVER AT OPPOSITE EXTREMITIES THEREOF AND AT EQUAL DISTANCES FROM SAID AXIS, COPLANAR ROLLERS OF EQUAL DIAMETER ROTATABLE ON SAID PINS, SAID ROLLERS, WITH SAID SHAFT ROTATING, DESCRIBING A CIRCLE ABOUT SAID AXIS, SAID CIRCLE HAVING A RADIUS EQUAL TO THE DISTANCE BETWEEN SAID AXIS AND THE PORTION OF EACH SAID ROLLER MOST REMOTE FROM SAID AXIS, A SUPPORT INCLUDING A SEMI-CIRCULAR SECTION AND TWO RECTILINEAR SECTIONS EXTENDING IN PARALLEL FROM THE EXTREMITIES OF SAID SEMI-CIRCULAR SECTION, SAID SEMI-CIRCULAR SECTION BEING PROVIDED WITH AN INWARDLY OPENING GROOVE FACING SAID SHAFT AND CONCENTRIC WITH SAID AXIS AND HAVING A RADIUS GREATER THAN THE FIRST SAID RADIUS, SAID RECTILINEAR SECTIONS DEFINING FACING GROOVES CONSTITUTING EXTENSIONS OF THE FIRST SAID GROOVE AND CONSTITUTING THEREWITH A RECEPTACLE OF GENERALLY ARCUATE CROSS-SECTION, AND A FLEXIBLE TUBE POSITIONED IN SAID RECEPTACLE AND OF A NORMALLY CIRCULAR CROSS-SECTION HAVING A DIAMETER GREATER THAN THE DIFFERENCE BETWEEN SAID RADII WHEREBY SAID ROLLERS ARE ADAPTED FOR LOCALLY AND PROGRESSIVELY COMPRESSING THE SAID TUBE, THE IMPROVEMENT CONSISTING OF A THREADED POST BETWEEN SAID RECTILINEAR SECTIONS, A PLATE SLIDABLY DISPLACEABLE ON SAID POST AND INCLUDING TWO EXTENSIONS ADAPTED FOR COMPRESSING SAID TUBE IN SAID RECTILINEAR SECTIONS TO THROTTLE LIQUID FLOW INTO AND OUT OF SAID TUBE, THE LATTER SAID EXTENSIONS INCLUDING GENERALLY TRIANGULAR EXTREMITIES FOR ENGAGING SAID TUBE, AND A KNOB ADJUSTABLE ON SAID POST AND ADAPTED FOR CONTROLLABLY DISPLACING SAID PLATE AND TRIANGULAR EXTREMITIES TOWARDS SAID TUBE. 